Well-casing spear.



J. B. NORRIS. WELL UASING SPEAK,

APPLICATION FILED JULY 1, 1910.

985,197. Patented Feb.28, 1911.

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JOSEPH B. NORRIS, OF CORSICANA, TEXAS.

WELL-CASING SPEAR.

quently occurs that a section of a well (7515- ing must be withdrawneither because of its breakage or for other reasons. In order to removethe damaged casing section, a clamping device known as a casing spear islowered into the well, and after the casing spear has been introducedinto the section of casing to be removed, an upward tension upon thecasing spear causes it to clamp upon the casing so that the two may besimultaneously withdrawn from the well. In some cases, however, thesection which it is desired to remove is so securely positioned in thewell that it cannot be removed by this means. It then becomes desirableto detach the casing spear from the section in order that the former maybe withdrawn from the well.

It is therefore the object of the present invention to provide a casingspear which may be made to clamp automatically upon a section of wellcasing, and which also may be automatically released from the casing ifdesired without the necessity of lowering any further apparatus into thewell to accomplish this result.

A further object 01' the invention is to provide a device for thisservice that will be strong, durable, simple and efficient andcomparatively easy to construct, and also one which will not be likelyto get out of working order.

lVith these and various other objects in view myinvention has relationto certain novel features of construction and operation, an example ofwhich is described in the following specification and illustrated in theaccompanying drawing, wherein;

Figure 1 is a vertical sectlonal view through the axis of a section ofpipe casing showing the herein-described well casing spear positionedtherein, the position shown being that assumed by the parts of thedevice when it is first introduced into a section of casin Fig. 2 is asimilar sectional Specification of Letters Patent.

Application filed July 1, 1910.

Patented Feb. 28, 1911.

Serial No. 569,896.

view in which the well spear has been introduced into a casing and hasbeen subjected to an upward tension causing the device to clamp againstthe walls of the easing. Fig. 3 is a similar View illustrating theposition assumed by the parts of the spear when the effort to raise thepipe easing has been abandoned and the spear has been lowered in orderto release the clamping means. Fig. t is a cross section through Fig. 2taken on the line aa2.

Referring now more particularly to the drawing wherein like letters ofreference designate similar parts in all the figures, the letter Adesignates the section of well casing which it is desired to remove fromthe well.

The letter B designates an upwardly tapering mandrel which forms themain body of the casing spear. The upper extremity of this mandrel isthreaded to receive a section of pipe C, a plurality of which sectionsare connected together in order to lower the mandrel into the well. Uponthe mandrel B is mounted a serrated split collar the teeth of which arearranged in annular horizontal rings with their sharp edges upwardly directed. The inner wall of this collar is tapered to fit the mandrel, thediameter of theape'rture being such that the collar fits tightly uponthe mandrel at its middle portion. In the middle portion of the mandrelat oppositesides thereof dogs E are pivotally mounted upon pins F. Thesedogs are each in a slot G in the wall of the mandrel, and each dog isprovided with a slotted aperture H to receive the pin F adapting the dogto move laterally upon its supporting pin. The top and bottom surfacesof these dogs incline inwardly toward each other, and

at the junction of these surfaces each dog is acted upon-by a spring K.The two springs K are carried by a split collar L which is mountedwithin the tubular interior wall of the mandrel. and is restricted fromvertical displacement by a pin M. A spline N prevents rotation of thecollar D upon the mandrel without. interfering with its longitudinalmotion thereupon.

hen the casing spear is first introduced into a section of easing thedogs occupy the position illustrated in Fig. 1. The collar D occupiesits highest possible position relative to the mandrel B since frictionbetween the collar and the well casing retards the collar as the mandrelmoves down. When means, the mandrel is again lowered into :l}l1 e,. p0S1lZ-1O11 illustrated 1n Flg. 3, the dogs .throughthe action of thesprings K and asan upward pressure is exerted upon the mandrel throughthe pipe section's C, the

mandrel moves upward for a short period without affecting the collar D,but when the mandrel reaches the position shown in Fig. 2 during itsupward motion, it tightens upon the collar D and springs said collar.outwardly forcing the teeth ofthe latter into the wall of thecasing. Atthe same timethe dogs E are displaced inwardlyloy the collar JD,assu1ning.-tl1e position shown in .Fig. 2;

I-nthis position, the casing spear grips the pasing morefirmly as theamount of upward tension isincreased. If it be foundthat thecasingsection cannotbe withdrawn by this B being released or displacedoutwardly suming the position illustrated in Fig. 3 with tlieirupperedges pro ect1ng.- When anupward.pressureis now exerted uponthe mandrelthe dogs E will .s'upportthe lower .edge ofthevcollar 1D and preventsaid collar. tightenlng upon the ananclrel. The casing spear thereforemay be removed since the collar D will no longer act as a' clamp.

.It isolovious that thespring K may be i given other forms than thatillustrated withtion.

ontdeparting from the spirit of the inven- Wfanous other changes may bemade in theydetails of thedevice without sacriii cingits advantages ordeparting from the spirit of the invention.

\Vhat Iclaim is: a

1. In a casing spear, the combination with an upwardly tapering mandrelf a split collar mounted thereupon having a serrated outer surface, andhaving its inner surface tapered to conform with the mandrel, a dog'pivotally-mounted in the wall of-the mandrel adapted to be pressedinward by said collarwhen the latter tightens upon the mandrel, and aspring acting. upon said dog adapted toforce its upper corner outwardlyof the mandrel. provided with a transversely V slotted aperturereceiving the pivot, and a sprlng acting on said dog causing thclowerportion of the dog to pro ect fronrthe mandrel normally, and the upperedge thereof to project after the dog has been subjected to apartialrotation by beingpressed.inward by the aforesaid collar.

*In testimony whereof I have signed my name to .this specification inthepresence of two subscribing witnesses.

JOSEPH B. NORRlS.

Witnesses:

WV. M. Insulin, F. M. RUNDELL.

iG opies of this patent may be obtained for five cents eaclntbyaddressing the Commissioner of Patents,

- Washington, D. C.

